Fuel nozzle



April 2,1929. G. L, RoalNsoN 1,707,772

FUEL NOZZLE Fileduuly 1:5', 1925 2 sheets-snee@ 1 April 2, '1929. v 5. L. ROBINSON FUEL NOZZLE Filed July 13, 1925 2 sheets-sudar Patented Apr. 2, 1929.

UNITED STATES PATENT OFFICE.

GEORGE L. ROBINSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO BLAW-KNOX COMPANYLOF PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F NEW JERSEY.

FUEL N OZZLE.

Application filed J'uly 13, 1925. Serial No. 43,132.

The present invention relates to nozzles for introducing fuels into furnaces, and it particularly relates to means for introducing fuels into high temperature furnaces, such as O. H. Furnaces for melting steel, glass melting furnaces, and other high-temperature furnaces, in which it is necessary to provide water-cooled jackets through which the fuels are introduced into the melting or heating chambers.

The fuels which are used for such purposes are natural gas,cityI gas, coke oven gas, Water gas, producer gas, oil or tar, and often a combination of gaseous and liquid fuels is also used which sometimes complicates the Water cooled jackets for introducing the fuels. These jackets have to withstand extremely high temperatures, sometimes as high as 3200O F., and due to their size, which sometimes may reach a length of 10 to 12 feet and a diameter of l2 to 16 inches, and also due to the sometimes complicated construction, it has in the past been extremely hard to prevent cracking up of these water cooled jackets. The reason for this is probably the strains set up in the various pipes and parts, of which the jacket is built up, by the intense heat, which causes different heat expansion in the various parts. The present invention overcomes the difficulties resulting from high temperature and expansion.

The burner jackets to which this invention applies consist of an outer steel shell or pipe and inner tubes or pipes through which the fuel flows into the furnace, these tubes being surrounded by' water between the outer shell and the outside of the tubes in order that they may be kept from being destroyed by the intense heat. The invention embodies two main features, namely, the provision for unequal expansion, as the outer shell is subjected to higher temperature than the inner( tubes, and the method for connecting the inner tubes and the outer shell together.

In the accompanying drawings:

Figure 1 is a longitudinal sectional View of a preferred form of burner embodying the features of my invention;

Figure 2 is a section on the line II-II of Figure 1, on a slightly reduced scale;

Figure 3 isa view similar to Figure 1 of a modified form of burner;

Figure 4 is a section on the line IV-IV of Figure 3; and

Figures 5, 6 and 7 are longitudinal sectional views of nozzles showing three'dilferent arrangements of expansion joint at the rear end of the nozzle.

Referring to the construction shown in Figure 1, 2 and 3 designate separate tubes for injecting two different fuels into a furnace, say, tar and gas. These tubes are enclosed in an outer jacket 4 through which water or other cooling medium is circulated. The tubes and -jacket are Welded at the forward end of the nozzle to an end piece 5. At the rear end of the nozzle there is an end piece 6 to which the tubes 2 and 3 are connected by screw threaded connections as in ordinary pipe Work, although the tubes might be connected thereto by welding. This end piece has passages 7 and 8 therein through which the fuel is supplied to the tubes 2 and 3. The water is introduced into the water jacket through inlet pipes 9 which pass through the jacket and are welded thereto to make the joints tight. These inlet pipes project to-Y wards the front end of the nozzle so as to sup-V ply the cold water asnear to the front end thereof as possible. An outlet connection .10 for the outflow of cooling Water is located close to the rear end of the nozzle. The tubes for supplying the two materials, such as tar and gas, may have different shapes in order to introduce the fuels in the most suitable way. In Figures 1 and 2 the pipe 3 which serves to introduce the gas is shown flattened so the gas Will spread in a horizontal direction in the furnace. The front end of the nozzle may also be shaped to comply with the requirements of the particular furnace with which the nozzle is employed.

In the preferred form of nozzle shown in Figure 1, air used for combustion of the fuel enters the furnace around the nozzle and this air may be preheated. The modified form of nozzle shown in Figure 3 is constructed to supply part or all of the air required for combustion through the nozzle as ,well'as to supply fuel. In this modified construction there is one small tube 11 throughwhich the atomized tar or oil is introduced. This tube is surrounded by a water cooled jacket, made up of tubes 13 and 14. The cooling .water is supplied through inlet pipes 15 and the outflow is through an outlet connection 16.

The gas is vsupplied through the nozzle 12, which 1s so shaped and .placed that air is drawn into the ring shaped space 12a between the nozzle and the casting 12", which forms the outer `end of the water-cooled jacket.

' The inflow of air can be regulated by a movable disc 12". The 'inner pipe 13 of theA water-cooled jacket is threaded into casting- V12", but the outer pipe 14 is allowed .to slide v on the casting 12b, and tightness is obtained by a stuiling box 13"*.which is pressed against the packing by a ring 13", which is held by screws 13 of figure. I A

It is evident that any difference in expansion due to the heat between pipes 13 and 14: is taken up by motion of pipe 14; inthestuliing box 13a.

While referencel is made to supplying tar.

and gas through the tubes 2 and 3 in the con struction shown in Figure 1 and tar, gas and air through the tubes 11 and 13,` in the construction shown in Figure 3, it is immaterial so far as the invention is concerned what materials are supplied through the tubes.

The outer jacket will, of course, expand more than the inner` tubes when subjected to heat and one feature of the invention, as already pointed out, consists in providing an expansion joint at the rear end of the nozzle so that the inner tubes and outer acket may eX- pand or contract relative to each other while water is kept from leaking from the acket at the expansion joint by means of a packing box similar tothat in common use for the packing vof piston rods. Figures 5, 6, and 7 show three locations for this sliding joint, the arrangement shown in Figure. 5 corresponding to that shown in Figure 1. yReferring first to Figure 5, the inner tubes 17 and 18- are connected to the end piece 19 inl any suitable manner, as by screw connections or by welding. The end piece 20 is then welded to these tubes by welds 21 and 22. The end piece is in this case apiece of plate pressed into the proper shape as shown, and itisfeasible for the Welder to get at the tubes 17 and 18 where they join the end piece 21 at. this stage in the manufacture before the water jacket 23 is placed inposition. When thev welds 21 and 22Ahave been made, the

v jacket 23 is slipped over the end piece 19 and likewise welded to thel end piece 20 by the weld 24. A water tight expansion .jointis provided betweenthe rear end of the jacket 23 and the end piece 19 by means. of the which one is shown in the" weldedto the jacket, a' gland 26 sliding on the end piece 19 and bolted to the flange 25 by the bolts 27 and packing material 28.

. In the construction shown in Figure the ,stuffing boxy consists of a flange 29 integral with the end piece 30, a gland 31'sliding on 4the end piece and engaging packing material 32 'and thrust rods 33 threaded into the flange '29 4and engaging thegland 3l.

Figure 7 shows 'nozzle having only a single inner tube'34. This tube projects 'through the end piece 35 and has the gland 36 slidably mounted l'thereon. vThe gland is held against packing material 37 Aby screwsstu'ngbox which consists of aflange 25 38 .which pass through the gland and are screwed into the end piece.

It will be seen that by the present invention I have provided `a nozzle construction adapted to supply several diderent fuels through separate channels whereby the sev- -eral kinds ofv fuel may be supplied at the same time but in different uantities and under different -pressures an that this nozzle Vembodies the features of the expansion joint and the method of welding as hereinbefore described,

. While I have shown and described certain embodiments of my invention it win be un'- Y derstood that the invention is not limited to its illustrated embodiments but that it may curing'said gland to the rear end of said jacket, and packing material between said gland and the -rear end'of said jacket, substantially as described.

In testimonywhereof I have hereunto set my hand.

GEORGE L. RoBiNsoN.

lable on said end piece, adjustable means seico 

